ABSTRACT
This study aimed to predict some soil water contents and soil erodibility indices with a multilayer perceptron (MLP) artificial neural network (ANN) using remote sensing data (Landsat 8 OLI TIRS) and topographic variables from a digital elevation model (DEM) in a semi-arid ecosystem. In models, the input variables were derived from remote sensing imaging and DEM. The output variables were field capacity, wilting point, aggregate stability index, structural stability index, dispersion ratio, and clay flocculation index. This study was realized in the watersheds of the Koruluk dam, the Kizlarkalesi, and the Telme ponds built for agricultural irrigation in Gümüshane-Siran. The soil samples were obtained from two depths (0-10 cm and 10-20 cm) from 59 soil profiles. Besides field capacity, wilting point, and aggregate stability analysis, undispersed/dispersed sand, silt, clay contents, and organic matter analysis were performed due to their strong effect on soil moisture, soil water content, and erodibility indices. The correlation analysis results showed significant relationships between soil characteristics and soil water contents/soil erodibility indices. The remote sensing variables were derived from three Landsat images of 2015 (June, July, and September). The performance results of MLP ANN models predicted for soil water contents and erodibility indices ranged from 0.75 to 0.90 for R2, 0.046-4.115 for root mean square error (RMSE), 4.46-6.54 for normalized root mean square error (NRMSE), and 0.042-0.186 for mean absolute error (MAE). Topography was a more significant group of variables that affected soil water contents and soil erodibility indices and the feature importance of topography in the prediction was over 55%. The results showed that the use of topographic variables together with remote sensing variables in MLP ANN modeling increased the performance of the models.
Subject(s)
Remote Sensing Technology , Soil , Acetylcysteine , Clay , Ecosystem , Environmental Monitoring/methods , Neural Networks, Computer , Sand , Soil/chemistry , WaterABSTRACT
1-Pentamethylbenzyl-3-ethylimidazoliumsilver(I)bromide and 1,3-bis(pentamethylbenzyl)-4,5dimethylbenzimidazoliumsilver(I)bromide and their Ag+ complexes were synthesized and their polycrystal forms were produced by recrystallization in dichloromethane/Et2 O solvent system. Structural determinations were carried out by 1 H NMR and 13 C NMR with a Varian 400 NMR system using tetramethylsilane as internal standard and CDCl3 as solvent. The disappearance of acidic N-heterocyclic carbene proton showed the formation of Ag(I) complexes. Also, elemental analyses were carried out. Electron paramagnetic resonance (EPR) measurements were performed to determine the formed radical structure on the samples irradiated at the room temperature for 72 h by using 60 Co-source with dose rate of 0.680 kGy. The EPR measurements were carried out in the temperature range of 200 K-450 K. Identical radicals were determined on the irradiated compounds. It was observed that the shapes of the spectra of the samples were independent of the temperature but, the resonance line intensities changed linearly with the temperature. Also, it was detected that the free radical on the 1-pentamethylbenzyl-3-ethylimidazoliumsilver(I)bromide is not stable compared to that on the 1,3-bis(pentamethylbenzyl)-4,5dimethylbenzimidazoliumsilver(I)bromide. Copyright © 2016 John Wiley & Sons, Ltd.
ABSTRACT
A macrocyclic azocalix[4]arene (1) based ester derivative was synthesized. The single crystals of azocalix[4]arene were produced by slow evaporation of concentrated ethyl acetate solutions. These single crystals were exposed to (60) Co gamma rays with a dose rate of 0.980 kGy h(-1) for 48 and 72 h to produce a stable free radical. Electron paramagnetic resonance (EPR) measurements were performed in three mutually perpendicular planes of the single crystal in the magnetic field, in addition, temperature dependence of the EPR signal was studied between 120 K and 450 K. The spectra were found to be temperature and angular dependent. Analysis based on the spectra recorded showed that a free radical was formed by fission of a C-H bond. This radical is described as (â¢) Ca HCb H3 The averages of the principal values of the hyperfine parameters and g-factor are: g = 2.0034, AHa = 1.28 mT, AH1=H2 = 1.00 mT, and AH3 = 0.49 mT.
